1. Field of the Invention
The present invention relates to a log splitter with means for actuating an operating arm of a hydraulic cylinder by a log provided between relatively moveable wedge means and backing plate means in spaced apart first and second positions for splitting and for return when the split log is removed from between the positions. In particular, the present invention relates to a log splitter which is activated by a moveable pressure plate provided on the backing plate means.
2. Prior Art
A general description of log splitters appears in Popular Science pages 101 to 104 August 1979. The most pertinent prior art is generally described in U.S. Pat. Nos. 1,666,795; 3,280,864; 3,640,323; 3,760,854; 3,779,295; 3,938,567; 4,061,168; 4,076,062; 4,103,724; 4,116,251; 4,128,117 and 4,141,396. In general these patents describe power operated log splitters including a frame means having two spaced apart first and second positions, a hydraulic cylinder having an operating arm linearly moveable from an idle position in the first position towards the second position and a wedge means and a backing plate means, one of which is fixed and the other of which is mounted on the operating arm and is moveable in a line between the first and second positions for splitting logs positioned on the frame means.
U.S. Pat. No. 3,077,214 to Brukner is the closest known prior art to the present invention and describes a complex linkage means for automatically cycling the operating arm of a hydraulic cylinder. The cycling mechanism is particularly described at column 7, lines 26 to 53; column 10, lines 76 to 40 and column 11, lines 69 to column 12, line 6 of this patent. Basically a mechanical linkage is described, with a block to engage a projection of shoe 103 from the operating arm or ram 100 so as to automatically return the operating arm of the hydraulic cylinder to the idle position. The same linkage has a repeater block 290 on stop link 165 for engagement with the projection on shoe 103 to automatically cycle the arm 100 from the idle position. The Brukner patent describes a complicated mechanism for increasing the pressure for log splitting; however, the operating arm 100 moves a full stroke on each cycle.
Most logs are not cut to the exact same length and no two logs require the exact same splitting force. One log may split after the wedge has penetrated only an inch or so, another may require forcing the wedge half way or the entire length of the log as is the case with dry burley oak. The prior art hydraulic log splitters do not solve this problem and generally the operating arm moves the same stoke on each cycle which is time consuming and expensive. What is needed is a means for actuating the operating arm of the hydraulic cylinder in the presence of the unsplit log and which returns the operating arm to the idle position as soon as the log is split.